I was just asking... because there is this really weird unknow error where some pictures just dont work with a slide show.
I had this once and went to a couple of FCP forums to ask for help... I wasn't the only one with the problem either, there is this one picture that I never got into a DVD SP Slideshow. No matter what I did to it. Converted it in PS to different files, etc, etc. I even took a screen shot of the picture and didn't work. I sent the picture to other people and they couldn't get it to work either. I finally just left it out, oh well.
Maybe its like when you try to open a scan of a dollar bill in PS. Who knows.
Anyways back to your problem, look in the encoding log to see during which process the error occurs. Thats the file that your going to have to work on.
Is the audio compressed? Remember they add up on the DVD, when it comes to bitrate.
BTW the total DVD file size doesn't matter if you surpass the max biterate for only a fracction of a second.